[Skip to Navigation]
June 1990

Circadian Variation of Plasma Homovanillic Acid Levels Is Attentuated by Fluphenazine in Patients With Schizophrenia

Author Affiliations

From the Section of Clinical Studies, Clinical Neuroscience Branch, National Institute of Mental Health, Bethesda, Md. Dr Doran is now with the Department of Psychiatry, University of California at Davis, Sacramento; Dr Labarca is now with the Department of Psychiatry, Catholic University School of Medicine, Santiago, Chile; Dr Wolkowitz is now with the Langley-Porter Psychiatric Institute/University of California, San Francisco; Dr Roy is now with Long Island Jewish Hospital, New York, NY; and Dr Douillet is now with Sanoli Research Montpellier (France) Center.

Arch Gen Psychiatry. 1990;47(6):558-563. doi:10.1001/archpsyc.1990.01810180058009

• Plasma homovanillic acid (HVA) levels were measured hourly for a 24-hour period in 10 patients with schizophrenia during treatment with placebo and fluphenazine. Ten age- and sex-matched normal volunteers were similarly studied. Diet and activity were carefully controlled and monitored in both patients and controls. A circadian rhythm of the plasma HVA level was found in controls with a nadir in the afternoon and peak values in the early morning hours; when the patients were free from drugs, they showed a similar rhythm with lower amplitudes. Fluphenazine treatment significantly reduced the plasma concentrations of HVA and abolished the 24-hour rhythm. These data suggest that a 24-hour rhythm of the plasma HVA level exists in humans and that the amplitude of this rhythm may be less pronounced in patients with schizophrenia. Treatment with neuroleptic drugs reduces both the absolute levels and the normal circadian rhythm of the plasma HVA level.

Add or change institution